Railway track circuit apparatus



y 12, 1931- 04c. BETTISON 1,304,665

RAILWAY TRACK CIRCUIT APPARATUS Original Filed Jan. 22, 1930 5 54 12 10 11% 3g 6 Fig.5. g T ILA I 6 1 T A 24 2 55b 8 INVENTOR: 7 51* 6 Fig.4. D. C B tt 5 n 14 HAL WW Patented May 12, 1931 I UNITED STATES PATENT OFFICE,

DAVID C. BETT'ISON, OF OMAHA, NEBRASKA, ASSIGNOR F ONE-HALF TO FRANK W.

IFLEGING RAILWAY TRACK CIRCUIT APPARATUS Application filed January 22, 1930, Serial No. 422,556. Renewed March 13, 1931.

M used in combinations of this character, by

supplying a direct charging current to the battery under certain track circuit conditions.

I will describe several forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view showing one form of apparatus embodying my invention. Figs.

2, 3 and 4 are views showing modifications of the apparatus shown in Fig. 1 and also embodying my invention.

Similar reference characters refer to similar parts in. each of the views.

Referring first to Fig. 1, the reference characters 1 and 1 designate the track rails of a railway track, which rails are divided by insulated joints 2 to form a track section .A-B. A direct current track relay 8 is connected across the rails adjacent one end of this section. Located adjacent the other end of the section is a main transformer T, the primary 4 of which is connected with a source of alternating current which is not shownin the drawings. The secondary 5 of this transformer is connected across the track rails 1 and 1 through a primary battery 9 and primary 7 of an auxillary trans- 1 former T a current limiting resistance 6 being also included in the secondary c1rcu1t for the usual and well known purpose. A rectifier and an adjustable inductive reactor 11 are connected in series across the secondary circuit of the transformer T between the battery 9 and the auxiliary transformer primary 7. The secondary 8 of the auxiliary transformer T is provided with a circuit which includes the primary battery 9 and a second rectifier 12.

When the track ballast is dry and the track section AB is unoccupied, practically no alternating current will flow into the track rails, because of the high inductive reactance of the track relay 3 and the high value of the ballast resistance. When the track ballast is wet, however, or the track section is occupied, an appreciable amount of alternating current will be drawn from the transformer secondary 5, and this current flowing through the primary 7 of the auxiliary transformer T will induce an alternating potential in the secondary 8, with the result that unidirectional current will be furnished to the primary battery 9 to charge this battery. It follows that the amount of direct current supplied to the battery 9 is proportional to the amount of alternating current supplied to the track rails by transformer T. I hai e found from actual demonstration that the parts of the apparatus can be so adjusted that practically the entire direct currenttrack circuit load is furnished by the transformer T and the rectifiers 10 and 12, so that the battery 9 is called upon to supply current to the load only in case of failure of the alternating current supply. It follows that the life of the primary battery will be much longer than if this battery were required to furnish a considerable amount of current to the track circuit under ordinary conditions.

Referring now to Fig. 2, the apparatus is the same as that shown in Fig. 1, except that the rectifier 10 and reactor 11 are omitted, and a portion 5 of the secondary winding of transformer T is included in series with the rectifier 12 and the primary battery 9 in the secondary circuit for transformer T Under dry weather conditions very little alternating current will flow to the track circuit, and the unidirectional current supplied to the battery 9 will be limited by the impedance of winding 7, the high ballast resistance, and the high impedance of the track relay. When the track ballast is wet, however, or the track section is occupied, alternating current may be drawn from the transformer T, and this current flowing through the primary 7 will induce an alter- 10 nating potential in the secondary 8. During one-half of each Wave of this current, the flow of current in secondary 8 will be opposed by the rectifier 12, and during this half wavethe alternating current flowing in primary 7 will 'magnetize .the core of transformer T During the other half wave, the energy stored in the magnetic circuit of transformer T will discharge through winding 8, thereby adding "to'the electromotive :torce tending to cause the flow of current through the rectifier 12 and the battery; this stored energy will, therefore;

increase the charging current to thebattery to a Value above that which will flow when no alternating current is being drawn by the track circuit. With this apparatus, then, as with that shown in Fig. l, the amount of direct current supplied to battery 9 is proportional to the amount of alternating current supplied to the track rails by transformer T. 1

v In Fig 3, the secondary 5, battery 9 and primary 7 are connected in series as in'Fig. 1, but the secondary 8 and recti 12 are connected in seriesacross the circuit for sec ondary 5. Fig. 4: is substantially the same: as Fig. 2 except that the two portions of the "secondary of transformer T are electrically isolated. Inboth of these modifications, as in Figs. land 2, the amount of direct-current supplied to theprimary battery is automatically regulated by the amount" of alternating current flowing through the primary of the transformer T Although I have herein shown and described only a few formsoi' apparatus embodying my invention, it is understood that various changes and modifications may be made therein'within the scope of the appended claims without departing from the spiritand scope of my invention. Having thus described my invention, what I claim is: V

1. In combination, a section of railway track, a direct current track relay connected with the rails of said section, a main transformerthe primary of whichis; connected with a source of alternating current, and the secondary of which is connected across the rails of said-section through a primary battery and the primary of annuxi'l-iary transformer, anda circuit tor the secondary of-said auxiliary transformer including said batteryand a rectifier.

2. In combination, a section of railway track, a direct current track relay connected with'the rails of said section, a main trans former the primary of which is connected with a source of alternating current, and the'secondary of which is connected across the rails of said section through a primary battery and the primary of. an auxiliary transformer, airectifier and an inductiye react-or connected-1n series acrossthe secondary circuit of said main transformer between said battery and the auxiliary transformer primary, and a circuit for the secondary of said auxiliary transformer including said battery and a rectifier. I

3; In combination,a section cot-railway track, a directcurrent track relay connected with the rails of said section, a main transformer theprim-ary of which is connected "with a source of alternating current and a with a source of alternating current, and the secondary of which connected across-the railsoit said sectiont'hrough a primary battery and-the primary of an auxiliary trans- 0Zlll91",i2l circuit forithe secondary of said auxiliary transformer including said battery, and a rectitier and the secondary :oi? the mai 1 transformer;

-5. in ccmbination,a section of railway track, a track circuit for said section inclu'ca track relayconnected across the rails at one pcintand a source of alternating current and a battery connectedin series across the-railsat anothei poinuand means for supplying direct current to said battery from said alternating current source at a rate proportional to the amount 'o't'alternating current drawn from said source by said track circuit.

In testimony whereof I afiix my si nature.

DAVID c. BETTfsoN. 

